Powering off Raspberry Pi without proper shutdown could cause SD card corruption and force users to reflash SD cards time to time. By enabling this function NanoDLP listens to GPIO if state of GPIO changed to the required state, it will shutdown the printer during the idle mode and during the print it will stop the printer.
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<h4>Gradeful Shutdown</h4>
To complete power-off it is possible to use Raspberry Pi kernel parameters (config.txt) to let external controller know that Pi is switched off. So it can cut the power completely.
GPIO state changes just after complete Raspberry Pi shutdown.
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<dl class="dl-horizontal small">
	<dt>Name</dt>
	<dd>gpio-poweroff</dd>
	<dt>Info</dt>
	<dd> Drives a GPIO high or low on poweroff (including halt). Enabling this
        overlay will prevent the ability to boot by driving GPIO3 low.</dd>
        <dt>Load</dt>
        <dd>dtoverlay=gpio-poweroff,param=val</dd>
        <dt>Params</dt>
        <dd></dd>
        <dt>gpiopin</dt>
        <dd>GPIO for signalling (default 26)</dd>
        <dt>active_low</dt>
        <dd>Set if the power control device requires a
            high->low transition to trigger a power-down.
            Note that this will require the support of a
            custom dt-blob.bin to prevent a power-down
            during the boot process, and that a reboot
            will also cause the pin to go low.</dd>
        <dt>input</dt>
        <dd>Set if the gpio pin should be configured as
            an input.</dd>
        <dt>export</dt>
        <dd>Set to export the configured pin to sysfs</dd>
        <dt>timeout_ms</dt>
        <dd>Specify (in ms) how long the kernel waits for
            power-down before issuing a WARN (default 3000).</dd>
        <dt>Example</dt>
        <dd>dtoverlay=gpio-poweroff,gpiopin=20</dd>
</dl>

